2 . The military use radar satellites________ targets through clouds and at night.
军队用雷达卫星透过云雾和夜幕追踪目标。

3 . China needed its own powerful air force to protect and ________(防卫；保卫) themselves against knife attacks. (根据汉语提示单词拼写)

4 . The technique is being tried in classrooms________ what effects it may have.
这种方法正在课堂上试用，以评定其效果。

5 . To t________ (解决) this crisis, he chose to study agriculture and received an education at Southwest Agricultural College in Chongqing.(根据中英文提示填空)

8 . They use special chemicals to __________ the growth of crops.
他们使用特殊的化学品来刺激农作物生长。